Watermelon Spider Mite Management Trial
Watermelon Spider Mite Management Trial, 2012 – ‘Sangria’ watermelons were transplanted on May 25 at the University of Delaware’s Research and Education Center located near Georgetown, DE. Plots consisted of two 20 ft long rows on 7ft centers. Each treatment was replicated four times and arranged in a RCB design. Foliar treatments were applied with a CO2 pressurized back pack sprayer delivering 28 gpa at 40 psi on June 15 and 18 gpa@ 40 psi on July 18. Mite populations were evaluated by counting the number of mites per 10 plants before vining, the number of mites per 50 leaves after vining and the number of mite infested plants from May 29 through June 27 for treatment timing #1 and on July 16 pre-treatments and July 23 post treatment for treatment timing #2. Data were analyzed using Proc GLM and means were separated by Tukey’s mean separation test (P=0.05). 1. Early Season Treatment – June 15 Treatment Rate/Acre May 29 Pre-trt Oberon 2SC 8.5 oz 12.50a
Percent Mite Infested Plants 1 June 4 June 11 June 18 June 22 Pre-Trt Pre-Trt 3 DAT 7 DAT 5.00a 17.50a 10.00a 2.50a
June 27 12 DAT 0.00a
Sniper
6.4 oz
12.50a
20.00a
12.50a
15.00a
10.00a
10.00a
Hero EC
10.3 oz
10.00a
12.50a
12.50a
25.00a
20.00a
7.50a
Zeal WSP
2 oz
10.00a
10.00a
10.00a
22.50a
7.50a
0.00a
Zeal WSP
3 oz
7.50a
12.50a
5.00a
22.50a
0.00a
0.00a
Agri-Mek 0.15 EC Portal
16 oz
5.00a
12.50a
10.00a
27.50a
5.00a
0.00a
2 pts
17.50a
10.00a
10.00a
12.50a
7.50a
0.00a
Untreated
--
15.00a
17.50a
15.00a
27.50a
12.50a
2.50a
1
Means within a column followed by the same letter are not significantly different (Tukey’s; P=0.05).
Treatment
Rate/Acre
Mean Number Mites per 10 plants 1 May 29 June 4 Pre-trt Pre-Trt 3.50a 2.00a
Mean Number of Mites per 50 Leaves1 June 11 Pre-Trt 25.00a
June 18 3 DAT 1.50a
June 22 7 DAT 1.50a
June 27 12 DAT 0.00b
Oberon 2SC
8.5 oz
Sniper
6.4 oz
7.25a
11.25a
4.00a
14.75a
6.75a
10.75a
Hero EC
10.3 oz
11.50a
12.75a
6.25a
22.75a
12.75a
2.00ab
Zeal WSP
2 oz
1.75a
1.25a
48.50a
7.50a
0.00a
2.00ab
Zeal WSP
3 oz
6.00a
10.00a
0.75a
22.50a
0.75a
0.00b
Agri-Mek 0.15 EC Portal
16 oz
1.75a
9.00a
3.00a
16.75a
0.00a
0.00b
2 pts
11.75a
2.25a
10.50a
2.50a
0.50a
0.00b
Untreated
--
7.50a
47.25a
172.75a
36.50a
15.25a
2.75ab
1
Means within a column followed by the same letter are not significantly different (Tukey’s; P=0.05).
2. Late Season Treatment – July 18 Percent Mite Infested Plants 1 Treatment Rate/Acre
Mean Number Mites per 50 leaves1 July 16- Pre-trt July 23 – Post-trt
July 16- Pre-trt
July 23 – Post-trt
Oberon 2SC
8.5 oz
25.00ab
56.67a
140.5a
111.50a
Sniper
6.4 oz
45.00a
63.33a
479.8a
408.00a
Hero EC
10.3 oz
37.50ab
63.33a
341.3a
636.3a
Zeal WSP
2 oz
10.00b
10.00a
1.50a
11.30a
Zeal WSP
3 oz
17.50ab
26.67a
11.50a
25.00a
Agri-Mek 0.15 EC Portal
16 oz
10.00b
26.67a
4.80a
7.50a
2 pts
20.00ab
23.33a
17.80a
17.50a
Untreated
--
45.00a
63.33a
230.00a
460.50a
1
Means within a column followed by the same letter are not significantly different (Tukey’s; P=0.05)
Percent Mite Infested Plants 1 June 4 June 11 June 18 June 22 Pre-Trt Pre-Trt 3 DAT 7 DAT 5.00a 17.50a 10.00a 2.50a
June 27 12 DAT 0.00a
Sniper
6.4 oz
12.50a
20.00a
12.50a
15.00a
10.00a
10.00a
Hero EC
10.3 oz
10.00a
12.50a
12.50a
25.00a
20.00a
7.50a
Zeal WSP
2 oz
10.00a
10.00a
10.00a
22.50a
7.50a
0.00a
Zeal WSP
3 oz
7.50a
12.50a
5.00a
22.50a
0.00a
0.00a
Agri-Mek 0.15 EC Portal
16 oz
5.00a
12.50a
10.00a
27.50a
5.00a
0.00a
2 pts
17.50a
10.00a
10.00a
12.50a
7.50a
0.00a
Untreated
--
15.00a
17.50a
15.00a
27.50a
12.50a
2.50a
1
Means within a column followed by the same letter are not significantly different (Tukey’s; P=0.05).
Treatment
Rate/Acre
Mean Number Mites per 10 plants 1 May 29 June 4 Pre-trt Pre-Trt 3.50a 2.00a
Mean Number of Mites per 50 Leaves1 June 11 Pre-Trt 25.00a
June 18 3 DAT 1.50a
June 22 7 DAT 1.50a
June 27 12 DAT 0.00b
Oberon 2SC
8.5 oz
Sniper
6.4 oz
7.25a
11.25a
4.00a
14.75a
6.75a
10.75a
Hero EC
10.3 oz
11.50a
12.75a
6.25a
22.75a
12.75a
2.00ab
Zeal WSP
2 oz
1.75a
1.25a
48.50a
7.50a
0.00a
2.00ab
Zeal WSP
3 oz
6.00a
10.00a
0.75a
22.50a
0.75a
0.00b
Agri-Mek 0.15 EC Portal
16 oz
1.75a
9.00a
3.00a
16.75a
0.00a
0.00b
2 pts
11.75a
2.25a
10.50a
2.50a
0.50a
0.00b
Untreated
--
7.50a
47.25a
172.75a
36.50a
15.25a
2.75ab
1
Means within a column followed by the same letter are not significantly different (Tukey’s; P=0.05).
2. Late Season Treatment – July 18 Percent Mite Infested Plants 1 Treatment Rate/Acre
Mean Number Mites per 50 leaves1 July 16- Pre-trt July 23 – Post-trt
July 16- Pre-trt
July 23 – Post-trt
Oberon 2SC
8.5 oz
25.00ab
56.67a
140.5a
111.50a
Sniper
6.4 oz
45.00a
63.33a
479.8a
408.00a
Hero EC
10.3 oz
37.50ab
63.33a
341.3a
636.3a
Zeal WSP
2 oz
10.00b
10.00a
1.50a
11.30a
Zeal WSP
3 oz
17.50ab
26.67a
11.50a
25.00a
Agri-Mek 0.15 EC Portal
16 oz
10.00b
26.67a
4.80a
7.50a
2 pts
20.00ab
23.33a
17.80a
17.50a
Untreated
--
45.00a
63.33a
230.00a
460.50a
1
Means within a column followed by the same letter are not significantly different (Tukey’s; P=0.05)
